x86: use get_bios_ebda()

Use get_bios_ebda().

Signed-off-by: Akinobu Mita <akinobu.mita@gmail.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>

diff --cc arch/x86/kernel/head64.c
Simple merge

diff --cc arch/x86/kernel/setup_32.c
Simple merge

diff --cc arch/x86/kernel/summit_32.c
Simple merge